evo 1340 Cylinder Base Gasket Leak

I recently had to replace left side engine crank seal due to oil leaking past and overfilling primary case. Oil leaking past the check valve into engine and I think pressure from excess oil in engine where it doesn't belong blew out seal. NOW, the base gasket on rear cylinder started to leak. Can the excess oil when engine sumps ( I think thats what its called?) cause this to happen?

The evo's had this weakness in the cylinder base gaskets and many had to change them because of seepage. I don't think that the excess oil had much to do with it. They eliminated this weakness with an "O" ring type of seal in the newer TC engines.

The evo's had this weakness in the cylinder base gaskets and many had to change them because of seepage. I don't think that the excess oil had much to do with it. They eliminated this weakness with an "O" ring type of seal in the newer TC engines.

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I just thought it was weird that it never leaked since I put the new cylinders and gaskets on until the engine seal went. I guess it was just a coincidence. Wonder what is next?

If I get an Evo on my lift that needs base gaskets they're automatically machined to make them flat again.Evo XL's too.I used to lap them but they're getting older and there's too much material for a lap to do the job.I do lap after cutting though.

I use Harley whenever possible.They're usually the best but I have been known to use case sealant on a cylinder that won't stop no matter what.I typically apply a thin coating of grease to the gasket before installing.Keeps the gasket from sticking to the cylinder/cases and allows some leeway for guys that can't warm their bikes up before pounding them.When you do that the cylinder dances around until it's warm and kills the gasket.the grease allows a little lube to keep the gasket from tearing.For a little while.

Yep. My rule of "thumb" is that I warm up my EVO to the point that the valve covers are nice and warm before riding off. Of course, warming up means at idle, not goosing the throttle!! By the way, use any finger to feel the warmth of the valve covers! he he ...

How true about the evo owners. They just don't understand how much the cylinders grow during warm up and when they beat on them before expansion is complete, away goes the base gasket in time. :60:

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OK, SO, what is the reason if you don't beat your bike up when it is cold as I always let it warm up. This started leaking after bike sat for 3 Months. I know, the bike was jealous cause I was riding the new one.:dknow